#include <stdio.h>

int main(int argc,char** argv)
{
    int a = 50;
    int b = 20;

    int* p = &a;
    int** p2 = &p;
    int*** p3 = &p2;

    *p2 = &b;
    **p2 = 30;

    printf("%i",b);

    return 0;
}